Suspension link for overhead contact wires and method of using same



May 1, 1928. 1,668,346

, T. VARNEY SUSPENSION LINK FOR OVERHEAD CONTACT WIRES AND METHOD OF USING SAME Filed May 2, 1925 ENTOR.

- I BY ATTORNEY Patented May 1, 1928.

UNITED STATES PATENT OFFICE.

THEODORE V-ABNEY, OF SEWICKLEY, PENNSYLVANIA,

PANY OF AMERICA, 0F

sUsrnNsIoN LINK non OVERHEAD coNrrAca' WIRES AND METHOD on USING sniun.

Application filed m 2,

This invention is for an improvement in the suspension wires and cables, and particularly the wires, used in overhead contact wire suspensions for electric railways.

In overhead contact systems for electrical railways, particularly in installations for high-speed travel, the cont-act wire is suspended from a supporting or catenary cable, in such manner as to be as nearly parallel with the roadbed as'possible, and with suflicient flexibility to yield slightly under the pressure of the collecting pantograph. A too rigid suspension of the contact wire results in distortion to the contact wire and excessive sparking.

. To this end, it is generally found desirable to suspend the contact cable indirectly from the catenary by means of an intervening supporting or messenger cable. As a matter of practice, the messenger cable is usually suspended from the catenary by a series of vertical rods which are rigid. The contact cable or cables, as there may be a plurality, are suspended from this messenger by a more or less sinuous cable, referred to as a lacing cable.

In order to maintain the contact cables in parallelism with the roadbed, it is necessary that some or all of the rods between the catenary and the messenger be slightly adjustable as to length, and for this purpose, rods for adjustment have generally been formed of two sections connected by an oppositely threaded union to form a connection of the turnbuckle type.

An important object of the present invention is to provide a suspension link to take the place of such a rod, which has greater flexibility than the rod and which is more cheaply constructed, easily variable as to length, and which will require less work in the field than the usual type of rod. A further object is to provide a method of using such a link.

It has also been found highly desirable, because of its light weight, to use as a catenary an aluminum cable with a steel core, and to use an aluminum messenger cable. -With such an arrangement, the catenary and messen er may be in good electrical contact wit% the contact wire, thereby providing a path of high electrical conductivity, which eliminates the necessity for heavy low voltage feeder wires along the right of way, the

1825. Serial No. 27,498.

catenary and the messenger serving this purpose. With such an arrangement, howevfir, all connections must be good electrica y. Y

A further object of the present invention is to provide a variably adjustable link which will form a good electrical contact between the ditferent cables of such a system.

The link may be used in either a system wherein the contact cable is suspended from a messenger cable, or directly from the catenary without the provision of a messenger, or in any other system wherein it maybe advantageously adapted.

The nature of the invention may be readily understood by reference to the accompanying drawings, wherein:

Fig. 1 is a diagrammatic view illustrating the adaptationof a form of the invention to ASSIGNOR TO ALUMINUM COM- I PITTSBURGH, PENNSYLVANIA, CORPORATION 01 PENN- an otherwise common system of suspension;

Fig. 2 is a side elevation of a link embodying the invention;

Fig. 3 is an end view of a form of clamp shown in Fig. 2, without the stranded cable being shown;

Fig. 4: is a detail view of a clamp which may be used in a system where the messenger cable is eliminated;

It will be understood that the drawings are for the purpose of illustrating the invention, but that various changes are within the contemplation of the various embodiments shown, and that the invention is not restricted to. any particular construction or overhead system of suspension.

Referring first to Figs. 1 to 8 inclusive,5 designates a main supportin or catenary cable having spaced apart insu ated points of suspension 6. Hung from the cable 5 is a messenger cable 7 from which is suspended the contact cable or cables 8, by means of the lacing cable 9.

passed a suitable suspension element, preferably in comprising a length of' stranded aluminum or other metal cable 15. The tube is preferably pressed or tightly fitted on the cable to insure good electrical contact.

One or more bolts or screws 10 may be utilized to hold the clamp sections together.

The ends of this length of cable 15 are preferably brought together within a tube 16 similar to tube 13, and frictionally or otherwise held therein. This tube 16 is engaged in a lower clamp 17, in all respects similar to clamp 10, butinverted with respect there to. This clamp engages the messenger cable, and makes a good electrical contact therewith. The messenger cable and the contact wire are, as usual, in good electrical connection.

With this construction, therefore, the cables of the system are all in good electrical contact to form a good conducting system. At the same time, the cable 15 does not possess the rigidity of the rod heretofore used, and therefore lends added flexibility to the system.

In order to vary the effective length of the link to adjust it to the articular point of the line where it is use one clamp, 10 or 17, is fastened to its respective cable. The other clamp is then rotated, twisting the cable 15 as indicated at 15. The more the cable is twisted, the shorter the effective length of the link becomes. When it has been adjusted to the desired length, the other clamp may be secured to its cable, thereby preventing the cable from untwisting. In Fig. 2, the dot and dash lines represent the original form of the link, while the full lines show it twisted.

This provides .a Very simple manner and method for adjustin the length of the suspension element, and one which permits of fabrication at a plant without further operations in the field, except that of twisting. It provides a suspension element which may be cheaply manufactured, which is flexible,

convenient to adjust, and capable of adjustment within the desired limits, and yet one which has ample strength.

The particular function of the tubes 13 and 16 is to insure good electrical contact, prevent cutting or mutilation of the cable 15, and provide thimbles to receive cables 15 to prevent the sharp bending thereof.

Instead of using the link between the sup- 7 porting cable and a messenger cable, it may be desirable to eliminate the messenger cable and suspend the contact wire directly from the supporting cable; In Fig. 4,1 have illustrated a clamp 20 having tongue-like ends, adaptedto engage the specially sha ed contact wire 21 o the usual kind. T is clamp also enga "es the looped cable 22 corresponding to ca le 15 of Fig. 2. The suspension link and the method 0 head suspension than those described. While the invention; relates primarily to electric railway overhead contact systems, it is not necessarily restricted to such use.

I claim as my invention:

1. The combination with a main supporting wire and a secondary wire suspended therefrom, of a suspension link for electrically connecting the two, said link including a twisted flexible loop member having a wire engaging clamp at each end thereof, said clamp being in binding contact Ivgvith the respective wires and the loop mem- 2. The combination with a main supporting wire, a messenger wire and a contact wire, of a suspension link for electrically connecting the supporting wire and-the messenger wire, means connecting the messenger wire and the contact wire, said link including a flexible adjustable loop member and wire engaging elements constituting with the means connecting the messenger and the contact wires an electrical connector between the said wires and providing a path of high electrical conductivity therebetween.

3. An-electrical connecting link for overhead suspension systems and the like including an elongated twisted wire loop having a metal cable-engaging clamp tightly connected" with each end thereof.

4. A connecting link ,for overhead suspension systems and the like including an elongated loop of twisted stranded cable, and acable-engaging clamp at each end of V the loop tightly connected therewith, whereby one cable may be flexibly suspended from another and the two maintained in good electrical contact.

'5. A. connecting link for overhead suspension systems and the like including an elongated loop of wire having a tube tightly fitted to each end of the loop, a thimble extension at each end of each tube, and a cable engaging clamp on each tube.

6'. In a systemof overhead suspension, a catenary cable, a messenger cable, and alower contact cable suspended from the messenger cable, and suspension connectors between the cables including an elongated wire loop having a metal cable-engaging clamp tightly secured to the top thereof and engaging the'catenary, and a similar clamp tightly connected with the bottom end thereof and connected with the messenger cable.

7. In a system of overhead suspension, a catena cable and a lower cable electrically suspended therefrom, and suspension connectors between the cables including an elongated wire loop having a metal cable-ens ging clamp tightly secured to the top t ereof and engaging the catenary, and a similar clamp tightly connected with the ice 7 fitted at each end of the loop, and a cable engaging clamp at each end of the link arranged in binding contact with the tube and link.

In testimony whereof I afiix my signature.

THEODORE VARNEY. 

